Chiral separations of underivatized arylpropionic acids by capillary zone electrophoresis with various cyclodextrins Acidity and inclusion constant determinations

Simultaneous chiral discrimination of multiple profens by cyclodextrin‐modified capillary electrophoresis in normal and reversed polarity modes

“…2A). In good agreement with previous reports [14,19,24,10], the negatively charged (R)- (2)-enantiomers of the three profens and (S)- (2)-naproxen formed more stable diastereomeric inclusion complexes with TMbCD than their corresponding enantiomers, thus migrating faster toward the cathode (detector) in the NP mode. In contrast, the (S)- (2)-isomers of the three profens (peaks 1, 3 and 9) and (R)-(1)-naproxen (peak 4) migrated ahead of their corresponding enantiomers in the RP mode (Fig.…”

“…Hence, the production of active profens in enantiomerically pure forms, their optical purity control and stereoselective pharmacokinetic studies have become important tasks in the chiral drug development [4][5][6][7][8]. These tasks could be more effectively conducted in high-throughput analysis mode by simultaneous enantioseparation of multiple profens in a single run [9][10][11][12] rather than in more commonly employed individual profen analysis mode [13][14][15][16][17][18][19][20][21][22][23][24][25].…”

“…Single CD system approaches employed either uncharged CDs such as heptakis(2,3,6-tri-O-methyl)-b-CD (TMbCD) [9-11, 14, 16, 19, 21, 24], hydroxypropyl-b-CD [13,21] and cyanoethylated b-CD [18], or charged CDs such as anionic sulfated b-CD [23], cationic b-CD-heptakis(6-methoxyethylamine) [12] and permethyl-6-monoamino-6-monodexyl-b-CD (PMMAbCD) [25]. They were operated in the conventional normal polarity (NP) mode [10,14,19,24] or more preferentially in the reversed polarity (RP) mode [9, 11-13, 16, 18, 21, 23]. For the enhancement of selectivity and resolution, dual CD system approaches have been explored by combining neutral TMbCD having the highest enantioselectivity toward profens with anionic sulfobutyl-b-CD (SBbCD) or carboxymethyl-b-CD (CMbCD) [5,15,20], heptakis-6-sulfato-b-CD (HSbCD) [22,25], or cationic mono(6-amino-6-deoxy)-b-CD (bCDNH 2 ) [17].…”

Selector-selectand interactions in chiral capillary electrophoresis

“…2 illustrates this statement. According to most studies on enantioseparation of chiral arylpropionic acids these compounds are both weakly complexed and not enantioselectively recognized in their anionic form by most of the neutral CDs [22,23]. However, excellent splitting of the resonance signals due to stereoselective CICS is observed in an aqueous solution of ()-fenoprofen (FP) in the presence of b-CD.…”

Methods for the estimation of binding constants by capillary electrophoresis

“…Equations (14)- (17) can also be applied to nonaqueous CE systems [88]. Nonlinear regression of the CE binding isotherm was used to estimate binding constants for several chiral drugs to cyclodextrins dissolved in dimethylformamide, N-methylformamide, formamide, 6 M urea in water, and water.…”